Linear accelerator for accelerating charged particles used in certain kinds of radiotherapy apparatus for medical treatments, must be as small as possible in size, in particular in the case where the accelerator is arranged in the mobile head of an irradiation unit. Moreover, it is advantageous that such a linear accelerator exhibits:
A wide energy range; PA1 Facility for modifying the adjustable energy; PA1 A high efficiency.
It is an object of the present invention to obtain a linear accelerator having these characteristics.